Luminescence in Crystalline Organic Materials: From Molecules to Molecular Solids

Abstract Luminescent small, all‐organic molecules are of tremendous interest in materials and life science applications. Nevertheless, targeted design requires a basic understanding of the excited state deactivation pathways of the molecules themselves, and the modulations of the processes that occur in the solid state. This particularly concerns crystalline molecular solids, as here not only solid‐state rigidification contributes to these modulations, but specific intermolecular interactions as well. Starting from the molecular properties, this work carefully disentangles all intramolecular and intermolecular factors to the radiative and nonradiative processes in crystalline all‐organic molecular solids to provide guidelines for targeted molecular materials design.